The invention relates to a method and an apparatus for forming high quality surfaces on workpieces by placing the workpiece adjacent to a mold with the desired form of surface so that a gap is formed between the latter and the workpiece and curable resin is introduced into the gap. More specifically, the invention is concerned with the production of parabolic concave antennas.
A large number of different techniques are presently available for producing accurate castings in molds. Furthermore, casting methods have been proposed for filling up flaws in a blank or faulty component by placing it in contact with a mold and introducing any of a range of different casting materials such as a casting resin between the mold and the workpiece. This latter form of the method yields a negative replica of the mold with an accuracy which usually increases with a decrease in the size and unevenness of the gap to be filled between the material and the mold, since the casting materials introduced into it are generally subject to a volume-dependent degree of shrink on solidification. For casting within such small gaps vacuum or pressure methods may frequently be used. A disadvantage of such methods is the deformation of the workpiece occurring owing to the acting forces. Such deformation is unacceptable, more especially in the case of high precision molded components.
Furthermore, there are processes for the production of structures in which metallic or organic foil of various types is bonded to the workpiece. The foil is provided with a hot melt or other adhesive and is pressed on the workpiece mechanically, pneumatically or hydraulically. In such a process the aim is to produce a bonding gap which is as even as possible. The larger the areas to be bonded the greater the risk of gas inclusions. The coating necessarily alters the geometry and dimensions of the component.